Malabsorption Syndromes

Malabsorption is a clinical result, not a single diagnosis. Nutrients may be inadequately digested, fail to cross injured intestinal mucosa, or fail to reach the absorptive surface in usable form. The bedside pattern is often more useful than the label at first: persistent diarrhea or greasy stools, weight loss, anaemia, edema, neuropathy, or deficiencies of fat-soluble vitamins. Celiac disease and pancreatic exocrine insufficiency (PEI) illustrate two different failure points. In celiac disease, gluten triggers immune-mediated villous injury, reducing intestinal absorptive surface. In PEI, the intestinal lining may be intact, but inadequate pancreatic enzymes prevent effective digestion, especially of fat. That difference determines the workup and treatment: celiac testing depends on ongoing gluten exposure, whereas PEI is evaluated with fecal elastase-1 and treated with pancreatic enzyme replacement therapy (PERT). A patient with new gastrointestinal bleeding, peritoneal signs, severe rapid weight loss, or diarrhea that continues despite appropriate treatment is no longer a routine nutrition problem. Those findings require urgent escalation.